Needing seven runs off the final over to beat South Africa in this morning's World Twenty20 tournament Group 1 clash, New Zealand could only muster four to lose the match by two runs after finishing on 168 for eight.

Winning would've put the Black Caps within touching distance of a semifinal berth and that looked within their grasp for most of the 40 overs. But when it really counted they simply couldn't get bat on ball.

The magnificent Dale Steyn, who was tasked with delivering the final over, finished with figures of four for 17 and was simply too good for New Zealand's batsmen.

It was an incredible final six balls. Luke Ronchi nicked out to the first of them, Nathan McCullum came in and played and missed twice, before scything Steyn over extra cover for four. A second attempt failed next ball and he was brilliantly caught.

Through it all, Ross Taylor stood watching at the other end on 62 not out. New Zealand's best player couldn't get on strike until the final ball, after he and McCullum had crossed. Wanting three to win and two to tie, Taylor could only bunt the ball back up the pitch to Steyn, who ran him out.

It was cruel for the Black Caps. They played some excellent cricket, but couldn't close the deal and now need to beat the Netherlands and Sri Lanka in their final matches to have any chance of advancing out of the group. Defeat would've eliminated South Africa from that equation, but they now remain in the hunt with an identical one-win, one-loss record to New Zealand.

Earlier, conceding 70 runs in the last five overs of South Africa's innings, turned an outstanding bowling performance into something bordering a poor one.

New Zealand probably would've taken 170 for six, when Kyle Mills opened up with the new ball. But as the innings progressed and the Black Caps gradually chipped guys out and Mills and Nathan McCullum proved difficult to get away, restricting the Proteas to a total of under 160 looked a distinct possibility.

But Tim Southee went for 46 off his four overs for the second successive game, as the impressive JP Duminy started to manipulate the bowling wherever he fancied.

It's hitters that tend to grab headlines in this format. Duminy is someone who manoeuvres and caresses the ball and his 86 not out from 43 balls showed that method can be just as effective, as well as being more easy on the eye.

Most of his team-mates had swung ineffectually at everything, with opener Hashim Amla (41 off 40) the exception.

Mills had the ball on a string and finished with one for 29. Fourteen of those came from the final three deliveries he bowled, otherwise he was tremendous.

So too offspinner McCullum. Like Mills, the elder McCullum isn't the sort of player who brings people through the gate, but he's canny and consistent and his one for 24 was typical of the performances he delivers for the side.

Corey Anderson (two for 28 off three) was good again and it was a surprise not to see him bowl the final over. It had seemed like Kane Williamson's one over for 13 had been to used to fill Southee's allotment, with the latter having bowled three overs for 33.

But Southee was brought back and got hit again. In theory he's New Zealand's sprearhead and was once a very adept blockhole bowler.

He can't find that length now, though, and when he comes on at first change he tends to undo some of the good work Mills and Mitchell McClenaghan have done up front.

It's an unforgiving game, Twenty20. But the simple truth is Southee needs to bowl better.

New Zealand made slow, then steady, then great progress in reply. Sadly Martin Guptill gave it away again, falling in the same fashion that he had against England.

It was Albie Morkel's first ball, but Guptill decided it had to be pulled over the leg side and again only succeeding in top edging it skywards.

He'd made 22 from 25, after a sluggish start and potentially put the team in a hole. When you get in, you need to stay in and some useful momentum came to nought not long after when Brendon McCullum was stumped off Imram Tahir for four.

It was average cricket from McCullum and he'll know that.

Thankfully Kane Williamson was going great guns, on his way to compiling his best score for New Zealand in this format. Again, though, having made 51 in 34 balls, he got out to Dale Steyn after half-winning the game for his side.

Everything fell to Taylor. If he could be a hero, New Zealand might be semifinal bound. The alternative didn't bear thinking about.